(19)
(11) EP 0 438 060 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
16.10.1991 Bulletin 1991/42

(43) Date of publication A2:
24.07.1991 Bulletin 1991/30

(21) Application number: 91100101.4

(22) Date of filing: 02.01.1991
(51) International Patent Classification (IPC)5: H01J 61/34, H01J 61/073, H01J 61/36, H01J 61/10
(84) Designated Contracting States:
DE GB

(30) Priority: 14.01.1990 JP 5518/90

(71) Applicant: TOSHIBA LIGHTING & TECHNOLOGY CORPORATION
Minato-ku, Tokyo-To (JP)

(72) Inventors:
  • Honda, Kazuo
    Hiratsuka-shi, Kanagawa-ken (JP)
  • Matsuura, Atsushi
    Tsurumi-ku, Yokohama-shi (JP)
  • Sano, Hisanori
    Yokosuka-shi, Kanagawa-ken (JP)
  • Mori, Yasuki
    Yokosuka-shi, Kanagawa-ken (JP)

(74) Representative: Henkel, Feiler, Hänzel & Partner 
Möhlstrasse 37
81675 München
81675 München (DE)


(56) References cited: : 
   
       


    (54) Metal vapor discharge lamp of a single end type


    (57) A metal vapor discharge lamp has a small arc tube (3) of a single end type. The maximum and minimum thicknesses of the wall of the arc tube (3) and the ratio of the minimum thickness to the maximum thickness are set to the values in predetermined ranges. The set thicknesses prevents breakage of the arc tube (3) and deterioration of the lamp characteristics.






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